In the current semiconductor industry, integrated circuit products can be divided into three main categories: logic, memory and analog circuit. Among them, memory device accounted for a large proportion of the integrated circuit products. With the development of semiconductor technology and wide applications of the memory device, the memory device and other devices need to be simultaneously formed on a single chip to form an embedded semiconductor memory. For example, to embed the memory device in a central processing unit, the memory device needs to be compatible with a platform of the embedded central processing unit, while the specifications and the corresponding electrical performance of the original memory device still need to be maintained.
In general, the memory device needs to be compatible with an embedded standard logic device. For example, an embedded semiconductor device usually includes a logic region and a memory region. The logic region usually includes a logic device, and the memory region usually includes a memory device. With the development of memory technology, various types of semiconductor memories have emerged, including static random access memory (SRAM), dynamic random access memory (DRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (Flash). Because the SRAM has advantages of low power consumption and fast operating speed, the SRAM and fabrication method thereof are attracting more and more attention.
However, it is desirable to improve the performance of the SRAM in a semiconductor device and thus to improve the overall performance of the semiconductor device. The disclosed device structures and methods are directed to solve one or more problems set forth above and other problems.